Augmented reality systems having a virtual image overlaying an infrared portion of a live scene

ABSTRACT

A head-mounted display (HMD) for an augmented reality system allows a user to view an augmented scene comprising a real-world portion of a live scene combined with virtual images overlaying an infrared (IR) portion of the live scene. The HMD includes a head-wearable frame, a lens defining a user field of view (FOV), and a camera. The lens permits the user to view a live scene corresponding to the user FOV, and the camera is configured to capture a captured image of the live scene containing data indicative of an infrared (IR) portion of the live scene. The IR portion of the live scene includes reflected IR light above a predetermined threshold, such as an IR reflective background surface in a simulation environment. Based on the IR portion, a virtual image is displayed on an interior surface of the lens so that the virtual image overlays the IR portion.

TECHNICAL FIELD

The embodiments relate generally to an augmented reality system and, in particular, to an augmented reality system having a virtual image overlaying an infrared portion of a live scene.

BACKGROUND

Commercial simulators, such as flight simulators, are relatively large systems that require a substantial amount of space. A flight simulator, for example, may include a large dome on which imagery is projected. The flight simulator may also include multiple projectors and image generators, which are costly, require a substantial amount of power, and generate a substantial amount of heat, which in turn increases environmental cooling requirements.

On the other hand, simulators that utilize virtual reality (VR) headgear suffer a number of problems that detract from realism. For example, movements of the participant or other objects that would naturally be seen by the participant in a non-VR simulation, such as movement of a cockpit control by the participant's hand, are often not depicted in the imagery even though during such movement the user's hand would come within the field-of-view of the participant if the participant were not wearing the VR headgear. Accordingly, there is a need for a simulator system that also allows a user to simultaneously view real-world foreground objects against virtual background images as a composite scene, such as an augmented reality system.

Chroma key compositing is one method for creating a composite image or scene, but it is not well suited for use in a simulation environment using an augmented reality system that overlays real-world imagery in a live scene with virtual imagery. With conventional chroma key compositing, a foreground image containing one or more objects has a background portion of a predetermined color (typically a saturated shade of blue or green). A processing device removes the monochrome portion from the foreground image and replaces the monochrome portion with a corresponding portion of a second, background image. The objects in the foreground that do not contain the predetermined color are retained, making the foreground objects appear to be in front of the background image, thereby forming a composite image of the foreground objects against a different background. However, in an augmented reality system using a see-through lens, the part of the augmented scene is a real-world environment, such as a vehicle interior, being viewed through a lens of the augmented reality system. For chroma key to function, a portion of the real-world environment, such as a window region of the vehicle interior, must be covered with a bright monochrome surface. When the augmented reality system provides a virtual image corresponding to the monochrome portion of the scene to the user via the lens, however, the monochrome portion of the live scene will still be visible to the user through the lens, because the bright background tends to bleed through the virtual image displayed on the lens, thereby causing the virtual image to appear washed out, faded, and artificial.

SUMMARY

In one embodiment, a head-mounted display (HMD) for an augmented reality system allows a user to view an augmented scene comprising a real-world portion of a live scene combined with virtual images overlaying an infrared (IR) portion of the live scene. The HMD includes a head-wearable frame, a lens defining a user field of view (FOV), and a camera having a camera FOV registered to the user FOV. The lens permits the user to view a live scene corresponding to the user FOV, and the camera is configured to capture an image of the live scene containing data indicative of an IR portion of the live scene. The IR portion of the live scene includes reflected IR light above a predetermined threshold, such as from an IR reflective background surface in a simulation environment. For example, without being limiting, the live scene may be of a vehicle interior, with the IR portion corresponding to a window of the vehicle covered with an IR reflective material. The IR portion is captured by the camera despite being invisible to the user, and a virtual image registered to the IR portion is displayed on an interior surface of the lens so that the virtual image overlays the IR portion. For example, the virtual image could be an out the window (OTW) view of a landscape or other environment, which overlays the window of the vehicle in the live scene to simulate an actual OTW view from the vehicle interior. Unlike conventional chroma key techniques, which requires a bright background with saturated color in the visible spectrum to function, the IR reflective surface can be made significantly darker and less saturated in the visible spectrum without hindering the IR reflectivity of the IR reflective surface. This allows the virtual image to be viewed on an internal surface of a lens while simultaneously viewing a live scene through the lens. Because the IR portion is not required to be bright or saturated in the visible spectrum, the virtual image can be displayed on the interior surface of the lens without the IR portion of the live scene “bleeding through” or otherwise distorting the virtual image.

In one embodiment, a HMD is disclosed. The HMD comprises a head-wearable frame configured to be worn by a user. The HMD further comprises a lens coupled to the frame. The lens defines a user FOV. The lens comprises an interior surface configured to face the user. The HMD further comprises a camera coupled to the frame. The camera has a camera FOV registered to the user FOV. The camera is configured to capture a captured image of a live scene corresponding to the user FOV. The captured image comprises data indicative of an IR portion of the live scene. The IR portion comprises IR light in a predetermined IR wavelength band reflected above a predetermined threshold. The HMD further comprises a display device configured to display a virtual image on the interior surface of the lens. The virtual image is registered to the IR portion of the live scene based on the captured image. The virtual image overlays the IR portion of the live scene in the user FOV.

In another embodiment, an augmented reality system is disclosed. The system comprises an HMD comprising a head-wearable frame configured to be worn by a user. The HMD further comprises a lens coupled to the frame, the lens defining a user FOV. The lens comprises an interior surface configured to face the user. The HMD further comprises a camera coupled to the frame, the camera having a camera FOV registered to the user FOV. The camera is configured to capture a captured image of a live scene corresponding to the user FOV. The HMD further comprises a display device configured to display a virtual image on the interior surface of the lens. The system further comprises a simulation environment comprising an infrared (IR) reflective surface disposed in the live scene. The IR reflective surface is configured to reflect IR light to define an IR portion of the live scene. The virtual image is registered to the IR portion of the live scene on the interior surface of the lens. The virtual image overlays the IR portion of the live scene in the user FOV.

In another embodiment, a method of providing a virtual image to a HMD is disclosed. The method comprises determining an IR portion of a live scene based on a captured image of the live scene, the live scene corresponding to a user FOV defined by a lens of the head-mounted display. The IR portion comprises IR light in a predetermined IR wavelength band reflected above a predetermined threshold. The method further comprises displaying, via a display device of the head-mounted display, a virtual image on an interior surface of the lens. The virtual image is registered to the IR portion of the live scene based on the captured image. The virtual image overlays the IR portion of the live scene in the user FOV.

Those skilled in the art will appreciate the scope of the disclosure and realize additional aspects thereof after reading the following detailed description of the embodiments in association with the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure.

FIG. 1 is a diagram of an environment during a simulation according to one embodiment;

FIG. 2 is a diagram of a process for providing a virtual image corresponding to an infrared portion of a live scene of the environment of FIG. 1;

FIG. 3 is a diagram of an environment in which embodiments may be practiced, including the embodiment of FIGS. 1 and 2;

FIG. 4 is a block diagram of the environment during the simulation illustrated in FIG. 1, at a subsequent point in time to that illustrated in FIG. 1;

FIG. 5 is a diagram of the environment during the simulation illustrated in FIGS. 1 and 4, at a subsequent point in time to that illustrated in FIGS. 1 and 4;

FIG. 6 is a diagram of a head-mounted display for an augmented reality system according to an embodiment;

FIG. 7 is a block diagram of the augmented reality system according to an embodiment; and

FIG. 8 is a flowchart of a method for providing a virtual image to an HMD according to an embodiment.

DETAILED DESCRIPTION

The embodiments set forth below represent the information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims.

Any flowcharts discussed herein are necessarily discussed in some sequence for purposes of illustration, but unless otherwise explicitly indicated, the embodiments are not limited to any particular sequence of steps. The use herein of ordinals in conjunction with an element is solely for distinguishing what might otherwise be similar or identical labels, such as “first user” and “second user,” and does not imply a priority, a type, an importance, or other attribute, unless otherwise stated herein.

As used herein and in the claims, the articles “a” and “an” in reference to an element refers to “one or more” of the element unless otherwise explicitly specified.

As used herein, phrases using the term “infrared” or “IR” (e.g., “infrared light,” “infrared radiation,” “infrared illumination”) correspond to electromagnetic radiation (EMR) wavelengths between 700 nm and 1 mm. Sub-bands within the IR spectrum may include, without limitation, short-wavelength IR (SWIR) corresponding to wavelengths between 1.4 μm and 3 μm, mid-wavelength IR (MWIR), corresponding to wavelengths between 3 μm and 8 μm, and long-wave IR (LWIR) corresponding to wavelengths between 8 μm and 15 μm. Similarly, phrases using the term “visible” (e.g., “visible light,” “visible radiation,” “visible illumination”) correspond to electromagnetic wavelengths between 400 nm and 700 nm.

In one embodiment, a head-mounted display (HMD) for an augmented reality system allows a user to view an augmented scene comprising a real-world portion of a live scene combined with virtual images configured to overlay an infrared (IR) portion of the live scene. The HMD includes a head-wearable frame, a lens defining a user field of view (FOV), and a camera having a camera FOV registered to the user FOV. The lens permits the user to view a live scene corresponding to the user FOV, and the camera is configured to capture an image of the live scene containing data indicative of an IR portion of the live scene. The IR portion of the live scene includes reflected IR light above a predetermined threshold, such as from an IR reflective background surface in a simulation environment. For example, without being limiting, the live scene may be of a vehicle interior, with the IR portion corresponding to a window of the vehicle covered with an IR reflective material. The IR portion is captured by the camera despite being invisible to the user, and a virtual image registered to the IR portion is displayed on an interior surface of the lens so that the virtual image overlays the IR portion. For example, the virtual image could be an out the window (OTW) view of a landscape or other environment, which overlays the window of the vehicle in the live scene to simulate an actual OTW view from the vehicle interior. Unlike conventional chroma key techniques, which requires a bright background with saturated color in the visible spectrum to function, the IR reflective surface can be made significantly darker and less saturated in the visible spectrum without hindering the IR reflectivity of the IR reflective surface. This allows the virtual image to be viewed on an internal surface of a lens while simultaneously viewing a live scene through the lens. Because the IR portion is not required to be bright or saturated in the visible spectrum, the virtual image can be displayed on the interior surface of the lens without the IR portion of the live scene “bleeding through” or otherwise distorting the virtual image.

In this regard, FIG. 1 is a diagram of an augmented reality system 10 comprising a head-mounted display (HMD) 12 being worn by a user 14 in an environment 16. The HMD 12 has head-wearable frame 17 for supporting a lens 18 that defines a user field of view (FOV) 20 for the user 14 to view a live scene 22. As will be discussed below in detail with respect to FIG. 5, the lens 18 in this embodiment has an exterior surface 24 that is transmissive to light to provide a real-world portion 26 of the live scene 22, and an interior surface 28 that is reflective to light. As will be discussed in detail below, a virtual image portion (not shown) is provided to the interior surface 28 of the lens 18, so that the virtual image portion (not shown) overlays an IR portion 30 of the live scene 22. The IR portion 30 in this embodiment is the portion of the live scene 22 that contains a view of an IR reflective material 32.

The environment 16 in this embodiment contains a mock-up of a helicopter interior 34 including a cockpit interior 36 with a window region 38, seats 40, a center console 42, flight controls 44, a dashboard 46, and overhead displays 48, etc. In this embodiment, the user 14 is a passenger user (“passenger user 14” hereinafter) seated in the helicopter interior 34 behind a pilot user 50. For the purposes of this example, reference will be made to the live scene 22 being viewed by the passenger user 14. It should be understood, however, that the pilot user 50 may also be a participant in the helicopter simulation environment 16 and may also be wearing another HMD for providing an independent augmented reality scene 52 to the pilot user 50. From the perspective of the forward facing passenger user 14, the user FOV 20 of the passenger user 14 wearing the HMD 12 defines the live scene 22. The live scene 22 has an IR portion 30 that includes a portion of the window region 38 that is covered with the IR reflective material 32 in the background. The live scene 22 also has a real-world portion 26 that includes a portion of the dashboard 46 in the background and the pilot user 50 in the foreground, with the pilot user 50 in a line of sight between a portion of the dashboard 46, the window region 38, and the HMD 12, thereby partially obstructing the portion of the dashboard 46 and the window region 38.

By illuminating the IR reflective material 32 of the window region 38 with IR light of a predetermined wavelength, the IR reflective material 32 reflects a greater amount of IR light than the other parts of the helicopter interior 34 that have less IR reflectivity. The increased IR reflection by the IR reflective material 32 is not detectable by the passenger user 14 viewing the live scene 22, however, because IR light is outside the visible spectrum.

Turning now to FIG. 2, a diagram is provided illustrating an augmented reality scene 52 to the passenger user 14 according to the embodiment of FIG. 1. In this embodiment, the HMD 12 includes a camera 54 having a camera FOV that is registered to the user FOV 20 (not shown). The camera 54 captures an image 56 (“captured image 56” hereinafter) registered to the live scene 22 being viewed by the passenger user 14, and from the same perspective as the passenger user 14. For example, as with the live scene 22, the captured image 56 includes the same view of portions of the dashboard 46 and window region 38 in the background, and the same view of the pilot user 50 in the foreground partially obstructing a portion of the dashboard 46 and window region 38. The higher levels of IR light being reflected by the window region 38 are detected by an image sensor (not shown) of the camera 54, even though the IR light is not visible to the passenger user 14.

A processing device 58 associated with the HMD 12 determines the IR portion 30 of the live scene 22 by detecting the portions of the captured image 56 indicative of reflected IR light above a predetermined threshold. The threshold may include a brightness threshold, a temperature threshold, and/or another parameter associated with IR light.

The processing device 58 next associates the IR portion 30 with a virtual environment model 60, such as an out-the-window (OTW) image including outdoor scenery. In this embodiment, the processing device 58 is integrated into the HMD 12, but it should be understood that the processing device 58 may operate remotely from the HMD 12, such as via a network. The processing device 58 determines a virtual scene 62 within the virtual environment model 60 based on data associated with the simulation, the viewing position and orientation of the passenger user 14, and the live scene 22. The processing device 58 crops the virtual scene 62 to create a virtual image 64 corresponding to the shape of the IR portion 30 of the live scene 22, with a cropped portion 66 of the virtual environment model 60 omitted from the virtual image 64 so as to not overlay the real-world portion 26 of the live scene 22. The virtual image 64 is then provided to a display device 68 associated with the HMD 12, which in turn projects the virtual image 64 onto the interior surface 28 of the lens 18. The virtual image 64 overlays the IR portion 30 of the live scene 22 on the interior surface 28 of the lens 18, thereby providing an augmented scene 70 to the passenger user 14.

Unlike conventional chroma key compositing techniques, the embodiment of FIGS. 1 and 2 is particularly well-suited to see-through displays, such as the lens 18 of the HMD 12. As discussed above, conventional chroma key compositing processes a first image containing one or more objects having a monochrome background of a predetermined color (typically blue or green), and generates a composite image that replaces the monochrome portion of the first image with corresponding portions of a second image. However, when this technique is applied to a see-through display, such as the lens 18 of the HMD 12 of FIGS. 1 and 2, the bright monochrome background in the live scene 22 tends to bleed through the virtual image 64 through the lens 18, thereby causing the virtual image 64 to appear washed out, tinted, and artificial.

In the embodiment of FIGS. 1 and 2, on the other hand, the IR portion 30 may contain wavelengths in the infrared spectrum reflected at relatively high intensity, while remaining invisible to the passenger user 14. Thus, the IR light from the IR portion 30 does not affect or interfere with the passenger user 14 viewing the virtual image 64, which is registered by the HMD 12 to the IR portion 30 as part of the augmented scene 70. In some embodiments, the IR reflective material 32 may also include a material or surface that is absorbent to visible light while remaining reflective of infrared light. In this manner, the amount of visible light passing through the portion of the lens 18 corresponding to the IR portion 30 of the live scene 22 is minimized while still reflecting a large amount of infrared light. This reduction in visible light reaching the portion of the exterior surface 24 of the lens 18 corresponding to the IR portion 30 has the effect of reducing the translucency of reflections from the interior surface 28 of the lens 18 configured to overlay the IR portion 30 in the augmented scene 70, thereby allowing the virtual image 64 to overlay the IR portion 30 of the live scene 22 within the augmented scene 70 as a substantially opaque image.

Different types of IR wavelengths or bands may be used, including wavelengths and bands within the SWIR, MWIR, and LWIR bands. It should also be understood that other bands within the EMR spectrum may be used in place of IR light, such as, without limitation, ultraviolet (UV) light, corresponding to electromagnetic wavelengths between 100 nm and 400 nm.

In an alternative embodiment, the window region 38 of the helicopter interior 34 may be an actual window with the IR reflective material 32 being disposed on an external object, such as a wall. In this embodiment, the environment 16 outside the helicopter interior region 34 may be illuminated with IR light, which is reflected by the IR reflective material 32 into the helicopter interior region 34 through the window region 38 from outside the helicopter interior region 34. This embodiment may reduce computational cost because the IR light source is located outside the helicopter interior region 34 (i.e., the helicopter model). This in turn may improve the ability of the camera 54 to distinguish between the window region 38, through which the external IR light is visible, and the helicopter interior region 34, which is subjected to significantly less stray IR light from the external IR light source and allows for the camera 54 to more easily distinguish between the illuminated window region 38 and the less-illuminated helicopter interior region 34. As discussed above, when the camera 54 captures the captured image 56, the IR portion 30 corresponds to the portion of the IR reflective material 32 that is visible through the window region 38 from the user FOV 20.

Referring now to FIG. 3, a block diagram of the environment 16 of FIG. 1 in which embodiments may be practiced is illustrated. In this embodiment, the environment 16 includes the augmented reality system 10, including the helicopter interior 34 and the passenger user 14 wearing the HMD 12. The HMD 12 includes the head-wearable frame 17 that is configured to be worn by the passenger user 14. By way of non-limiting example, the head-wearable frame 17 may comprise any suitable structure that is capable of positioning one or more lenses 18 with respect to the eyes of the passenger user 14. The head-wearable frame 17, in one embodiment, may comprise an eyeglasses frame that couples to the head of the passenger user 14 via two extensions, or arms, that are supported by the ears of the passenger user 14, and a bridge that is supported by the nose of the passenger user 14. In another embodiment, the head-wearable frame 17 may comprise a flight helmet that is supported by the head of the passenger user 14.

While for purposes of discussion the lens 18 may be referred to in the singular, in some embodiments the lens 18 comprises two lenses: a right eye lens 18 and a left eye lens 18. In such embodiments, each lens 18 may have a FOV, which may be referred to as a right eye FOV and a left eye FOV, respectively. The right eye FOV and the left eye FOV collectively define an overall FOV corresponding to the user FOV 20 for the augmented reality system 10. There may be overlap between the right eye FOV and the left eye FOV, with appropriate overlapping imagery generated for each eye.

The augmented reality system 10 may also include a sensor 72 configured to generate sensor data that changes in response to movements of the head of the passenger user 14. In this embodiment, the sensor 72 may comprise any suitable sensor subsystem that is capable of generating data from which a location and an orientation of the head of the passenger user 14 can be determined. In another embodiment, the sensor 72 comprises an inertial measurement unit (IMU) that is coupled to the head-wearable frame 17. In some embodiments, the sensor 72 is configured to generate sensor data from which rotational and/or translational acceleration of the head of the passenger user 14 may be derived to facilitate predictions of head motion, to help reduce latency and/or lag in the imagery as the head of the passenger user 14 moves. In this manner, the sensor 72 allows the processing device 58 to determine a relative position and orientation of the user FOV 20 and determine a virtual FOV within the virtual environment model 60 based on the relative position and orientation of the user FOV 20, the virtual FOV defining a virtual scene 73. The processing device 58 is then able to determine a portion of the virtual scene 73 registered to the IR portion 30 of the live scene 22 to generate the virtual image 64.

A controller 74 provides various functionalities to the augmented reality system 10, as discussed in detail herein, and is coupled to the camera 54, the sensor 72, and/or to the display device 68. The controller 74 includes one or more processing devices 58 and a memory 76. At least some of the functionality provided herein may be provided via computer instructions that are stored in the memory 76 and executed by the processing device 58.

An image generator (IG) 78 generates the virtual image 64 corresponding to OTW imagery of a virtual environment that is presented to the passenger user 14 based at least in part on the virtual environment model 60 that is stored in the memory 76. The virtual environment model 60 contains data that defines the virtual environment, such as the visible surfaces and/or objects in the virtual environment, the states, attributes and characteristics thereof, as well as attributes and characteristics of the simulated vehicle, such as direction, altitude, speed, and the like. As will be discussed in greater detail below, the IG 78 determines a current FOV of the augmented reality system 10 based at least in part on the FOV of the lens 18 and the orientation and/or location of the head of the passenger user 14, accesses the virtual environment model 60 to determine the state of the virtual environment at that moment in time, and generates the virtual image 64. The virtual image 64 is then provided to the display device 68 for presentation to the passenger user 14. This process happens iteratively at a particular frame rate, such as, by way of non-limiting example, 30, 60, or 120 frames per second, even as the virtual environment may be concurrently changing, such that objects depicted within the virtual image 64 are moving with respect to the simulated vehicle. For example, the virtual image 64 may depict imagery that moves with respect to the helicopter interior region 34 as if the passenger user 14 were traveling in a moving helicopter. While for purposes of illustration the IG 78 is illustrated as being a component or element within the controller 74, this is merely one embodiment, and in other embodiments, the IG 78 may be separate from the controller 74 and may communicate with the controller 74 via a communications path.

While for purposes of illustration the virtual environment model 60 is illustrated as being maintained in the memory 76 of the controller 74, in other embodiments, the virtual environment model 60 may be maintained external to the augmented reality system 10. In particular, the virtual environment model 60 may be maintained by a device that is communicatively coupled to the augmented reality system 10, and to one or more other simulators, via a network, to allow for a multi-user simulation wherein other simulation systems, including possibly other augmented reality systems 10, access the virtual environment model 60 concurrently with the augmented reality system 10.

In one embodiment, the augmented reality system 10 has an ultra-wide user FOV 20, such as in excess of 100 degrees. As discussed above, the augmented reality system 10 also includes a display device 68 that is mapped to the interior surface 28 of the lens 18. In some embodiments, the augmented reality system 10 may comprise or include one or more components of the head-mounted display device described in U.S. Pat. No. 8,781,794 B2, entitled “METHODS AND SYSTEMS FOR CREATING FREE SPACE REFLECTIVE OPTICAL SURFACES,” filed on Aug. 17, 2011 and U.S. Patent Application Publication No. 2012/0120498 A1, entitled “HEAD-MOUNTED DISPLAY APPARATUS EMPLOYING ONE OR MORE FRESNEL LENSES,” filed on Aug. 17, 2011, each of which is hereby incorporated by reference herein.

The controller 74, via the IG 78, accesses the virtual environment model 60 and generates the virtual image 64, which visually depicts that portion of the virtual environment that is within the window region 38 of the user FOV 20. The IG 78 provides the virtual image 64 to the display device 68 to cause the display device 68 to emit light in accordance with the virtual image 64 toward the interior surface 28 of the lens 18, which is reflected into the eyes 82 of the passenger user 14. As noted above, the IR reflective material 32 of the window region 38 may be absorbent of visible light in addition to being reflective of infrared light, in order to reduce the translucency of reflections from the interior surface 28 of the lens 18.

As discussed above, the environment 16 in this embodiment contains a helicopter interior 34 including a cockpit interior 36, but it should be understood that other types of simulation environments 16 are contemplated. The helicopter interior 34 may also include lighting features to properly simulate the look of the helicopter interior 34 as if the passenger user 14 were in the vehicle being simulated. The cockpit interior 36 includes seats 40, a center console 42, flight controls 44, a dashboard 46, overhead displays 48, and a window region 38 having IR reflective material 32. In some embodiments, an actual aircraft may be used in a darkened hanger or other location, or which has a darkening material having an IR reflective material 32 placed over the window region 38 on the exterior or interior of the cockpit interior 36.

The process described above occurs at the particular frame rate of the augmented reality system 10, such as 30 frames per second. The sensor 72 generates sensor data that changes responsive to movements of the HMD 12, such as when the passenger user 14 moves his head, and thus, the particular virtual image 64 and the real-world portion 26 of the augmented scene 70 may continually change, as may happen if the actual vehicle being simulated were in motion.

In this regard, FIG. 4 is a diagram of the environment 16 during the simulation illustrated in FIG. 1, at a subsequent point in time to that illustrated in FIG. 1. In this embodiment, the live scene 22 is divided among a plurality of pixels 79. Each pixel 79 is mapped to a corresponding portion of the interior surface 28 of the lens 18. The display device 68 can thus precisely project the virtual image 64, on a pixel-by-pixel basis, in a way that each pixel 79 is projected precisely on a predetermined location of the interior surface 28 of the lens 18 such that the virtual image 64 will be reflected into the eye 82 of the passenger user 14. In this example, the virtual image 64 is projected from a portion of the pixels 79 of the display device 68 (not shown) corresponding to the IR portion 30 of the live scene 22. To help facilitate the view of the real-world portion 26 of the live scene 22 within the augmented scene 70, the display device 68 may turn off the pixels 79 corresponding to the real-world portion 26, to reduce reflections from the interior surface 28 of the lens 18 other than the portion from which the virtual image 64 is reflected. It should be understood that other methods may be used to provide the virtual image 64 to the interior surface 28 of the lens 18. For example, in some embodiments, the lens 18 may contain an integrated display device 68 (not shown), such as, for example, a see-through liquid crystal display (LCD). This embodiment enables direct view of the LCD display device 68 embedded within the lens 18 in the user FOV 30, rather than a reflected view of the interior surface 28 of the lens 18.

To display the virtual image 64, the processing device 58 determines, for each pixel 79 (or other type of predefined section) of the captured image 56, whether an IR brightness (or other parameter), is above the predetermined IR brightness threshold (or other threshold). The processing device 58 (not shown) registers each pixel 79 of the captured image 56 having an IR brightness above the IR brightness threshold to the IR portion 30 of the live scene 22.

Based on the processing device 58 determining the IR portion 30, the IG 78 determines a subset of pixels 79 of the display device 68 that corresponds to the IR portion 30 of the live scene 22. The IG 78 causes the subset of pixels 79 in the display device 68 to emit light in accordance with the virtual image 64 toward the interior surface 28 of the lens 18 so that the virtual image 64 is registered to the IR portion 30 of the live scene 22, thereby causing the virtual image 64 to overlay the IR portion 30 in the user FOV 20.

Again, while for purposes of discussion, the display device 68 may be referred to in the singular, in some embodiments the display device 68 comprises two display apparatuses: a right eye display apparatus that is mapped to the right eye lens 18, and a left eye display apparatus that is mapped to the left eye lens 18. Each pixel 79 of a respective display device 68 is mapped to a particular location on the interior surface 28 of a corresponding lens 18, such that light emitted from such pixel 79 will be reflected toward the eye 82 of the passenger user 14 from that particular location on the interior surface 28 of the corresponding lens 18. For example, each pixel 79 in the right eye display apparatus is mapped to a particular location on the interior surface 28 of the right eye lens 18. Light emitted from a respective pixel 79 of the right eye display device 68 is reflected from the particular location on the interior surface 28 of the right eye lens 18 that corresponds to that pixel 79 into the corresponding right eye 82 of the passenger user 14. Light emitted from other pixels 79 that do not correspond to that particular location on the interior surface 28 of the right eye lens 18 is not reflected into the right eye 82 of the passenger user 14 from that particular location of the interior surface 28 of the right eye lens 18. Similarly, the pixels 79 of the left eye display device 68 are mapped to particular locations on the interior surface 28 of the left eye lens 18.

In one embodiment, the controller 74 first generates FOV imagery that includes all objects in the virtual environment model 60 that would come within the entire user FOV 20. The location and orientation of the head of the passenger user 14 is used to generate a stencil that is used to modify the FOV imagery to remove, or mask, all FOV imagery that would overlay the real-world portion 26 that would otherwise be within the user FOV 20, to generate the virtual image 64. The virtual image 64 is then provided to the display device 68.

Referring now to FIG. 5, a diagram of the environment 16 during the simulation illustrated in FIG. 1 is depicted at a subsequent point in time. In this example, the passenger user 14 has tilted his head, thereby tilting the HMD 12. As the HMD 12 tilts, the camera 54 (not shown) continually captures images 56 and the sensor 72 continually generates sensor data that identifies a location and orientation of the head of the passenger user 14 in relation to the virtual environment model 60. The controller 74 (not shown) determines the live scene 22 based on the captured image 56. The live scene 22 includes the window region 38 defining the IR portion 30, and a portion of the dashboard 46 and pilot user 50 defining the real-world portion 26. The controller 74, via the IG 78 (not shown), accesses the virtual environment model 60 and generates virtual image 64, which visually depicts that portion of the virtual environment that is within the window region 38. The IG 78 provides the virtual image 64 to the display device 68 to cause the display device 68 to emit light in accordance with the virtual image 64 toward the interior surface 28 of the lens 18, which is reflected into the eyes of the passenger user 14.

In one embodiment, the camera 54 may provide some or all of the functionality of the sensor 72. For example, the camera 54 may capture landmarks within the captured image 56 that can be correlated to real-time positions and orientations of the HMD 12 by the processing device 58. These landmarks could be features in the cockpit interior 36, for example, or could be fiducial markers, i.e., objects positioned in the camera FOV for use as a point of reference.

FIG. 6 is a diagram of the HMD 12 according to one embodiment. In this embodiment, the camera 54 and/or sensor 72 (not shown) may be coupled directly to the head-wearable frame 17. The head-wearable frame 17 may also include an IR light source 80 configured to shine IR light on a portion of the helicopter interior region 34 within the user FOV 20, including the IR reflective material 32 in the window region 38. As discussed above, the IR reflective material 32 may be configured to reflect more IR light than the other regions of the helicopter interior 34, thereby allowing the camera 54 to capture a captured image 56 having data indicative of a clearly defined and easily detectible IR portion 30 within the live scene 22.

The display device 68 is positioned above an eye 82 of the passenger user 14 and oriented such that the display device 68 can project light onto the interior surface 28 of the lens 18. A cable 84 may provide a path for communications between the camera 54, sensor 72, display device 68, and the controller 74 (not shown), as well as power for the camera 54, sensor 72, and/or display device 68, as needed.

It should be understood that the HMD 12 may alternatively be configured as a more fully immersive display. In this regard, the lens 18 may be opaque to visible light, such that the only imagery in the user FOV 20 would be the virtual image 64 being reflected by the interior surface 28 of the lens 18. Alternatively, the lens 18 could be substituted with a mirror (not shown). In this embodiment, the entire augmented scene 70 would be provided to the interior surface 28 of the lens 18 by the display device 68, with the augmented scene 70 including the virtual image 64 combined with the real-world portion 26 of the captured image 56, rather than the actual view of the real-world portion 26. In this embodiment, the real-world portion 26 of the captured image 56 is composited with the virtual image 64 to create a composite image corresponding to the augmented scene 70. The composite image of the augmented scene 70 is then provided to the reflective interior surface 28 of the lens 18. In this embodiment, the camera 54 may be configured to capture the captured image 56 in the visibile spectrum and the IR spectrum simultaneously, or multiple cameras 54 could be used. In this embodiment, a first camera 54 is configured to capture the captured image 56 in the visible spectrum to provide the real-world portion 26 to the IG 78, and a second camera 54 (having substantially the same camera FOV) is configured to capture the IR portion 30 of the captured image 56 so that the virtual image 64 can be composited with the real world portion 26 of the captured image 56.

FIG. 7 is a block diagram of the augmented reality system 10 according to one embodiment. As discussed above, the augmented reality system 10 may have any desirable form factor, such as, by way of a non-limiting example, a flight helmet or head-wearable frame 17. The augmented reality system 10 includes the processing device 58, the memory 76, and a system bus 86. The system bus 86 provides an interface for system components including, but not limited to, the memory 76, the processing device 58, the display device 68, the camera 54, the sensor 72, etc. The processing device 58 can be any commercially available or proprietary processing device or processing devices.

The system bus 86 may be any of several types of bus structures that may further interconnect to a memory bus (with or without a memory controller), a peripheral bus, and/or a local bus using any of a variety of commercially available bus architectures. The memory 76 may include a volatile memory 88 (e.g., random access memory (RAM)) and/or a non-volatile memory 90 (e.g., read only memory (ROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), etc.). A basic input/output system (BIOS) 92 may be stored in the non-volatile memory 90, and can include the basic routines that help to transfer information between elements within the augmented reality system 10. The volatile memory 88 may also include a high-speed RAM, such as static RAM for caching data.

The augmented reality system 10 may further include or be coupled to a computer-readable storage 94, which may comprise, for example, an internal or external hard disk drive (HDD) (e.g., enhanced integrated drive electronics (EIDE) or serial advanced technology attachment (SATA)), HDD (e.g., EIDE or SATA) for storage, flash memory, or the like. The computer-readable storage 94 and other drives, associated with computer-readable media and computer-usable media, may provide non-volatile storage of data, data structures, computer-executable instructions, and the like. Although the description of computer-readable media above refers to an HDD, it should be appreciated by those skilled in the art that other types of media which are readable by a computer, such as floppy disks, magnetic cassettes, flash memory cards, cartridges, and the like, may also be used in the exemplary operating environment, and further, that any such media may contain computer-executable instructions for performing novel methods of the disclosed architecture.

A number of modules can be stored in the computer-readable storage 94 and in the volatile memory 88, including an operating system 96 and one or more program modules 98, which may implement the functionality described herein in whole or in part. It is to be appreciated that the embodiments can be implemented with various commercially available operating systems 96 or combinations of operating systems 96.

A portion of the embodiments may be implemented as a computer program product stored on a transitory or non-transitory computer-usable or computer-readable storage medium, such as the computer-readable storage 94, which includes complex programming instructions, such as complex computer-readable program code, configured to cause the processing device 58 to carry out the steps described herein. Thus, the computer-readable program code can comprise software instructions for implementing the functionality of the embodiments described herein when executed on the processing device 58. The processing device 58, in conjunction with the program modules 98 in the volatile memory 88, and in some embodiments the IG 78, may serve as the controller 74 for the augmented reality system 10 that is configured to, or adapted to, implement the functionality described herein.

The augmented reality system 10 may also include a communication interface 100, suitable for communicating with a network as appropriate or desired. The IG 78 may comprise any suitable proprietary or off-the-shelf IG, such as an NVIDIA® or AMD® graphics card.

FIG. 8 is a flowchart of a method 200 for providing the virtual image 64 to the HMD 12 of FIGS. 1-3 according to one embodiment, and will be discussed in conjunction with FIGS. 1-3. The method 200 includes determining an IR portion 30 of a live scene 22 based on a captured image 56 of the live scene 22 (block 202). As discussed above, the live scene 22 corresponds to the user FOV 20 defined by the lens 18 of the HMD 12. The method 200 further includes displaying, via the display device 68 of the HMD 12, the virtual image 64 on the interior surface 28 of the lens 18 (block 204). As discussed in detail above, the virtual image 64 is registered to the IR portion 30 of the live scene 22 based on the captured image 56, with the virtual image 64 overlaying the IR portion 30 of the live scene 22 in the user FOV 20.

Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow. 

What is claimed is:
 1. A head-mounted display (HMD) comprising: a head-wearable frame configured to be worn by a user; a lens coupled to the frame, the lens defining a user field of view (FOV), the lens comprising an interior surface configured to face the user; a camera coupled to the frame, the camera having a camera FOV registered to the user FOV, the camera configured to capture a captured image of a live scene corresponding to the user FOV, the captured image comprising data indicative of an IR portion of the live scene, the IR portion comprising an infrared (IR) light in a predetermined IR wavelength band reflected above a predetermined threshold; a processing device configured to: detect the IR portion of the live scene based on the captured image; determine the virtual image based on the IR portion by: determining a relative position and orientation of the user FOV; determining a virtual FOV within a virtual environment model based on the relative position and orientation of the user FOV, the virtual FOV defining a virtual scene; and registering a portion of the virtual scene to the IR portion of the live scene to determine the virtual image; and a display device configured to display the virtual image on the interior surface of the lens, the virtual image registered to the IR portion of the live scene based on the captured image, the virtual image configured to overlay the IR portion of the live scene in the user FOV.
 2. The HMD of claim 1, wherein the predetermined threshold is an IR brightness threshold, the processing device further configured to: determine, for a plurality of predefined sections of the captured image, whether an IR brightness of each section in the predetermined IR wavelength band is above the IR brightness threshold; and register each section of the captured image having an IR brightness above the IR brightness threshold to the IR portion of the live scene.
 3. The HMD of claim 2, wherein the plurality of predefined sections of the captured image is a plurality of pixels, each pixel mapped to a predetermined location of the interior surface of the lens.
 4. The HMD of claim 1, wherein the interior surface of the lens comprises a reflective surface, and wherein the display device is configured to project the virtual image on the reflective surface of the lens, the virtual image configured to overlay the IR portion of the live scene.
 5. An augmented reality system comprising: a head-mounted display (HMD) comprising: a head-wearable frame configured to be worn by a user; a lens coupled to the frame, the lens defining a user field of view (FOV), the lens comprising an interior surface configured to face the user; a camera coupled to the frame, the camera having a camera FOV registered to the user FOV, the camera configured to capture a captured image of a live scene corresponding to the user FOV; and a display device configured to display a virtual image on the interior surface of the lens; a simulation environment comprising an infrared (IR) reflective surface disposed in the live scene, the IR reflective surface configured to reflect IR light to define an IR portion of the live scene; and a processing device configured to: detect the IR portion of the live scene based on the captured image by: determining, for a plurality of predefined sections of the captured image, whether an IR brightness of each section in a predetermined IR wavelength band is above an IR brightness threshold; and registering each section of the captured image having an IR brightness above the IR brightness threshold to the IR portion of the live scene; and determine the virtual image based on the IR portion; wherein the virtual image is registered to the IR portion of the live scene on the interior surface of the lens, the virtual image configured to overlay the IR portion of the live scene in the user FOV.
 6. The augmented reality system of claim 5, wherein the IR reflective surface in the live scene comprises a window region of the simulation environment.
 7. The augmented reality system of claim 5, further comprising an object disposed in the live scene in a line of sight between a portion of the IR reflective surface in the live scene and the HMD.
 8. The augmented reality system of claim 5, wherein the IR reflective surface in the live scene is configured to reduce a translucency of the virtual image.
 9. The augmented reality system of claim 8, wherein the IR reflective surface in the live scene is configured to absorb visible light to reduce the translucency of the virtual image.
 10. The augmented reality system of claim 5, wherein the plurality of predefined sections of the captured image is a plurality of pixels, each pixel mapped to a predetermined location of the interior surface of the lens.
 11. The augmented reality system of claim 1, wherein the interior surface of the lens comprises a reflective surface, and wherein the display device is configured to project the virtual image on the reflective surface of the lens, the virtual image configured to overlay the IR portion of the live scene.
 12. A method of providing a virtual image to a head-mounted display (HMD), the method comprising: determining an infrared (IR) portion of a live scene based on a captured image of the live scene, the live scene corresponding to a user field of view (FOV) defined by a lens of the HMD, the IR portion comprising IR light in a predetermined IR wavelength band reflected above a predetermined threshold; determining a relative position and orientation of the user FOV; determining a virtual FOV within a virtual environment model based on the relative position and orientation of the user FOV, the virtual FOV defining a virtual scene; registering a portion of the virtual scene to the IR portion of the live scene to determine the virtual image; and displaying, via a display device of the HMD, the virtual image on an interior surface of the lens, the virtual image registered to the IR portion of the live scene based on the captured image, the virtual image configured to overlay the IR portion of the live scene in the user FOV.
 13. The method of claim 12, wherein the IR portion corresponds to an IR reflective surface disposed in the live scene, the IR reflective surface configured to reflect IR light in the predetermined IR wavelength band.
 14. The method of claim 13, further comprising an object disposed in the live scene in a line of sight between a portion of the IR reflective surface in the live scene and the HMD.
 15. The method of claim 13, wherein the IR reflective surface in the live scene is configured to reduce a translucency of the virtual image overlaying the IR portion of the live scene in the user FOV.
 16. The method of claim 15, wherein the IR reflective surface in the live scene is configured to absorb visible light to reduce the translucency of the virtual image overlaying the IR portion of the live scene in the user FOV.
 17. A head-mounted display (HMD) comprising: a head-wearable frame configured to be worn by a user; a lens coupled to the frame, the lens defining a user field of view (FOV), the lens comprising an interior surface configured to face the user; a camera coupled to the frame, the camera having a camera FOV registered to the user FOV, the camera configured to capture a captured image of a live scene corresponding to the user FOV, the captured image comprising data indicative of an IR portion of the live scene, the IR portion comprising an infrared (IR) light in a predetermined IR wavelength band reflected above an IR brightness threshold; a processing device configured to: determine, for a plurality of predefined sections of the captured image, whether an IR brightness of each section in the predetermined IR wavelength band is above the IR brightness threshold; register each section of the captured image having an IR brightness above the IR brightness threshold to the IR portion of the live scene; and determine the virtual image based on the IR portion; and a display device configured to display the virtual image on the interior surface of the lens, the virtual image registered to the IR portion of the live scene based on the captured image, the virtual image configured to overlay the IR portion of the live scene in the user FOV. 